Light emitting panel assemblies

ABSTRACT

Light emitting panel assemblies include light emitting panel members and one or more light sources positioned/embedded in a light transition area, which increases the efficiency of light entering the panel members along the light input area to be emitted from one or more light emitting surfaces along the length of the panel members. Light may be reflected or refracted by a surface which changes the path of a portion of light such that it enters the input area of the panel member at a more acceptable angle. A uniform light output distribution may be produced by utilizing a pattern of light extracting deformities.

This is a continuation of co-pending application Ser. No. 08/495,176filed on Jun. 27, 1995.

BACKGROUND OF THE INVENTION

This invention relates generally, as indicated, to light emitting panelassemblies each including a transparent panel member for efficientlyconducting light, and controlling the light conducted by the panelmember to be emitted from one or more light output areas along thelength thereof.

Light emitting panel assemblies are generally known. However, thepresent invention relates to several different light emitting panelassembly configurations which provide for better control of the lightoutput from the panel assemblies and for more efficient utilization oflight, which results in greater light output from the panel assemblies.

SUMMARY OF THE INVENTION

In accordance with one aspect of the invention, the light emitting panelassemblies include a light emitting panel member having a lighttransition area in which at least one light source is suitably mountedfor transmission of light to the light input surface of the panelmember.

In accordance with another aspect of the invention, the light source isdesirably embedded, potted or bonded to the light transition area toeliminate any air gaps, decrease surface reflections and/or eliminateany lens effect between the light source and light transition area,thereby reducing light loss and increasing the light output from thepanel assembly.

In accordance with another aspect of the invention, the panel assembliesmay include reflective or refractive surfaces for changing the path of aportion of the light, emitted from the light source, that would notnormally enter the panel members at an acceptable angle that allows thelight to remain in the panel members for a longer period of time and/orincrease the efficiency of the panel members.

In accordance with another aspect of the invention, the light emittingpanel members include a pattern of light extracting deformities ordisruptions which provide a desired light output distribution from thepanel members by changing the angle of refraction of a portion of thelight from one or more light output areas of the panel members.

In accordance with still another aspect of the invention, the lightsource may include multiple colored light sources for supplying light toone or more light output areas, and for providing a colored or whitelight output distribution.

In accordance with yet another aspect of the invention, the panelassemblies include a transition area for mixing the multiple coloredlights, prior to the light entering the panel members, in order toeffect a desired colored or white light output distribution.

The various light emitting panel assemblies of the present invention arevery efficient panel assemblies that may be used to produce increaseduniformity and higher light output from the panel members with lowerpower requirements, and allow the panel members to be made thinnerand/or longer, and/or of various shapes and sizes.

To the accomplishment of the foregoing and related ends, the inventionthen comprises the features hereinafter fully described and particularlypointed out in the claims, the following description and the annexeddrawings setting forth in detail certain illustrative embodiments of theinvention, these being indicative, however, of but several of thevarious ways in which the principles of the invention may be employed.

BRIEF DESCRIPTION OF THE DRAWINGS

In the annexed drawings:

FIGS. 1 through 3 are schematic perspective views of three differentforms of light emitting panel assemblies in accordance with thisinvention;

FIG. 4a is an enlarged plan view of a portion of a light output area ofa panel assembly showing one form of pattern of light extractingdeformities on the light output area;

FIGS. 4b, c and d are enlarged schematic perspective views of a portionof a light output area of a panel assembly showing other forms of lightextracting deformities formed in or on the light output area;

FIG. 5 is an enlarged transverse section through the light emittingpanel assembly of FIG. 3 taken generally on the plane of the line 5--5thereof;

FIG. 6 is a schematic perspective view of another form of light emittingpanel assembly in accordance with this invention;

FIG. 7 is a schematic top plan view of another form of light emittingpanel assembly in accordance with this invention;

FIG. 8 is a schematic perspective view of another form of light emittingpanel assembly in accordance with this invention;

FIG. 9 is a schematic top plan view of another form of light emittingpanel assembly in accordance with this invention;

FIG. 10 is a schematic top plan view of still another form of lightemitting panel assembly in accordance with this invention;

FIG. 11 is a side elevation view of the light emitting panel assembly ofFIG. 10;

FIG. 11a is a fragmentary side elevation view showing a tapered orrounded end on the panel member in place of the prismatic surface shownin FIGS. 10 and 11;

FIG. 12 is a schematic top plan view of another form of light emittingpanel assembly in accordance with this invention;

FIG. 13 is a schematic side elevation view of the light emitting panelassembly of FIG. 12; and

FIGS. 14 and 15 are schematic perspective views of still other forms oflight emitting panel assemblies in accordance with this invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now in detail to the drawings, and initially to FIG. 1, thereis schematically shown one form of light emitting panel assembly 1 inaccordance with this invention including a transparent light emittingpanel 2 and one or more light sources 3 which emit light in apredetermined pattern in a light transition member or area 4 used tomake the transition from the light source 3 to the light emitting panel2, as well known in the art. The light that is transmitted by the lighttransition area 4 to the transparent light emitting panel 2 may beemitted along the entire length of the panel or from one or more lightoutput areas along the length of the panel as desired to produce adesired light output distribution to fit a particular application.

In FIG. 1 the light transition area 4 is shown as an integral extensionof one end of the light emitting panel 2 and as being generallyrectangular in shape. However, the light transition area may be of othershapes suitable for embedding, potting, bonding or otherwise mountingthe light source. Also, reflective or refractive surfaces may beprovided to increase efficiency. Moreover, the light transition area 4may be a separate piece suitably attached to the light input surface 13of the panel member if desired. Also, the sides of the light transitionarea may be curved to more efficiently reflect or refract a portion ofthe light emitted from the light source through the light emitting panelat an acceptable angle.

FIG. 2 shows another form of light emitting panel assembly 5 inaccordance with this invention including a panel light transition area 6at one end of the light emitting panel 7 with sides 8, 9 around andbehind the light source 3 shaped to more efficiently reflect and/orrefract and focus the light emitted from the light source 3 thatimpinges on these surfaces back through the light transition area 6 atan acceptable angle for entering the light input surface 18 at one endof the light emitting panel 7. Also, a suitable reflective material orcoating 10 may be provided on the portions of the sides of the lighttransition areas of the panel assemblies of FIGS. 1 and 2 on which aportion of the light impinges for maximizing the amount of light orotherwise changing the light that is reflected back through the lighttransition areas and into the light emitting panels.

The panel assemblies shown in FIGS. 1 and 2 include a single lightsource 3, whereas FIG. 3 shows another light emitting panel assembly 11in accordance with this invention including two light sources 3. Ofcourse, it will be appreciated that the panel assemblies of the presentinvention may be provided with any number of light sources as desired,depending on the particular application.

The panel assembly 11 of FIG. 3 includes a light transition area 12 atone end of the light emitting panel 14 having reflective and/orrefractive surfaces 15 around and behind each light source 3. Thesesurfaces 15 may be appropriately shaped including for example curved,straight and/or faceted surfaces, and if desired, suitable reflectivematerials or coatings may be provided on portions of these surfaces tomore efficiently reflect and/or refract and focus a portion of the lightemitted for example from an incandescent light source which emits lightin a 360° pattern through the light transition areas 12 into the lightinput surface 19 of the light emitting panel 14.

The light sources 3 may be mechanically held in any suitable manner inslots, cavities or openings 16 machined, molded or otherwise formed inthe light transition areas of the panel assemblies. However, preferablythe light sources 3 are embedded, potted or bonded in the lighttransition areas in order to eliminate any air gaps or air interfacesurfaces between the light sources and surrounding light transitionareas, thereby reducing light loss and increasing the light outputemitted by the light emitting panels. Such mounting of the light sourcesmay be accomplished, for example, by bonding the light sources 3 in theslots, cavities or openings 16 in the light transition areas using asufficient quantity of a suitable embedding, potting or bonding material17. The slots, cavities or openings 16 may be on the top, bottom, sidesor back of the light transition areas. Bonding can also be accomplishedby a variety of methods that do not incorporate extra material, forexample, thermal bonding, heat staking, ultrasonic or plastic welding orthe like. Other methods of bonding include insert molding and castingaround the light source(s).

A transparent light emitting material of any suitable type, for exampleacrylic or polycarbonate, may be used for the light emitting panels.Also, the panels may be substantially flat, or curved, may be a singlelayer or multi-layers, and may have different thicknesses and shapes.Moreover, the panels may be flexible, or rigid, and may be made out of avariety of compounds. Further, the panels may be hollow, filled withliquid, air, or be solid, and may have holes or ridges in the panels.

Each light source 3 may also be of any suitable type including, forexample, any of the types disclosed in U.S. Pat. Nos. 4,897,771 and5,005,108, assigned to the same assignee as the present application, theentire disclosures of which are incorporated herein by reference. Inparticular, the light sources 3 may be an arc lamp, an incandescent bulbwhich also may be colored, filtered or painted, a lens end bulb, a linelight, a halogen lamp, a light emitting diode (LED), a chip from an LED,a neon bulb, a fluorescent tube, a fiber optic light pipe transmittingfrom a remote source, a laser or laser diode, or any other suitablelight source. Additionally, the light sources 3 may be a multiplecolored LED, or a combination of multiple colored radiation sources inorder to provide a desired colored or white light output distribution.For example, a plurality of colored lights such as LEDs of differentcolors (red, blue, green) or a single LED with multiple colored chipsmay be employed to create white light or any other colored light outputdistribution by varying the intensities of each individual coloredlight.

A pattern of light extracting deformities or disruptions may be providedon one or both sides of the panel members or on one or more selectedareas on one or both sides of the panel members, as desired. FIG. 4aschematically shows one such light surface area 20 on which a pattern oflight extracting deformities or disruptions 21 is provided. As usedherein, the term deformities or disruptions are used interchangeably tomean any change in the shape or geometry of the panel surface and/orcoating or surface treatment that causes a portion of the light to beemitted. The pattern of light extracting deformities 21 shown in FIG. 4aincludes a variable pattern which breaks up the light rays such that theinternal angle of reflection of a portion of the light rays will begreat enough to cause the light rays either to be emitted out of thepanel through the side or sides on which the light extractingdeformities 21 are provided or reflected back through the panel andemitted out the other side.

These deformities or disruptions 21 can be produced in a variety ofmanners, for example, by providing a painted pattern, an etched pattern,a machined pattern, a printed pattern, a hot stamped pattern, or amolded pattern or the like on selected light output areas of the panelmembers. An ink or printed pattern may be applied for example by padprinting, silk screening, ink jet, heat transfer film process or thelike. The deformities may also be printed on a sheet or film which isused to apply the deformities to the panel member. This sheet or filmmay become a permanent part of the light panel assembly for example byattaching or otherwise positioning the sheet or film against one or bothsides of the panel member similar to the sheet or film 27 shown in FIGS.3 and 5 in order to produce a desired effect.

By varying the density, opaqueness or translucence, shape, depth, color,area, index of refraction, or type of deformities 21 on an area or areasof the panels, the light output of the panels can be controlled. Thedeformities or disruptions may be used to control the percent of lightemitted from any area of the panels. For example, less and/or smallersize deformities 21 may be placed on panel areas where less light outputis wanted. Conversely, a greater percentage of and/or larger deformitiesmay be placed on areas of the panels where greater light output isdesired.

Varying the percentages and/or size of deformities in different areas ofthe panel is necessary in order to provide a uniform light outputdistribution. For example, the amount of light traveling through thepanels will ordinarily be greater in areas closer to the light sourcethan in other areas further removed from the light source. A pattern oflight extracting deformities 21 may be used to adjust for the lightvariances within the panel members, for example, by providing a denserconcentration of light extracting deformities with increased distancefrom the light source 3 thereby resulting in a more uniform light outputdistribution from the light emitting panels.

The deformities 21 may also be used to control the output ray angledistribution of the emitted light to suit a particular application. Forexample, if the panel assemblies are used to provide a liquid crystaldisplay backlight, the light output will be more efficient if thedeformities 21 cause the light rays to emit from the panels atpredetermined ray angles such that they will pass through the liquidcrystal display with low loss.

Additionally, the pattern of light extracting deformities may be used toadjust for light output variances attributed to light extractions of thepanel members. The pattern of light extracting deformities 21 may beprinted on the light output areas utilizing a wide spectrum of paints,inks, coatings, epoxies, or the like, ranging from glossy to opaque orboth, and may employ half-tone separation techniques to vary thedeformity 21 coverage. Moreover, the pattern of light extractingdeformities 21 may be multiple layers or vary in index of refraction.

Print patterns of light extracting deformities 21 may vary in shapessuch as dots, squares, diamonds, ellipses, stars, random shapes, and thelike, and are desirably 0.006 square inch per deformity/element or less.Also, print patterns that are 60 lines per inch or finer are desirablyemployed, thus making the deformities or shapes 21 in the print patternsnearly invisible to the human eye in a particular application therebyeliminating the detection of gradient or banding lines that are commonto light extracting patterns utilizing larger elements. Additionally,the deformities may vary in shape and/or size along the length and/orwidth of the panel members. Also, a random placement pattern of thedeformities may be utilized throughout the length and/or width of thepanel members. The deformities may have shapes or a pattern with nospecific angles to reduce moire or other interference effects. Examplesof methods to create these random patterns are printing a pattern ofshapes using stochastic print pattern techniques, frequency modulatedhalf tone patterns, or random dot half tones. Moreover, the deformitiesmay be colored in order to effect color correction in the panel members.The color of the deformities may also vary throughout the panel members,for example to provide different colors for the same or different lightoutput areas.

In addition to or in lieu of the patterns of light extractingdeformities 21 shown in FIG. 4a, other light extracting deformitiesincluding prismatic surfaces, depressions or raised surfaces of variousshapes using more complex shapes in a mold pattern may be molded,etched, stamped, thermoformed, hot stamped or the like into or on one ormore areas of the panel member. FIGS. 4b and 4c show panel areas 22 onwhich prismatic surfaces 23 or depressions 24 are formed in the panelareas, whereas FIG. 4d shows prismatic or other reflective or refractivesurfaces 25 formed on the exterior of the panel area. The prismaticsurfaces, depressions or raised surfaces will cause a portion of thelight rays contacted thereby to be emitted from the panel member. Also,the angles of the prisms, depressions or other surfaces may be varied todirect the light in different directions to produce a desired lightoutput distribution or effect. Moreover, the reflective or refractivesurfaces may have shapes or a pattern with no specific angles to reducemoire or other interference effects.

As best seen in the cross sectional view of FIG. 5, a back reflector(including trans reflectors) 26 may be attached or positioned againstone side of the panel member 14 of FIG. 3 using a suitable adhesive 28or other method in order to improve light output efficiency of the panelassembly 11 by reflecting the light emitted from that side back throughthe panel for emission through the opposite side. Additionally, apattern of light extracting deformities 21, 23, 24 and/or 25 may beprovided on one or both sides of the panel member in order to change thepath of the light so that the internal critical angle is exceeded and aportion of the light is emitted from one or both sides of the panel.Moreover, a transparent film, sheet or plate 27 may be attached orpositioned against the side or sides of the panel member from whichlight is emitted using a suitable adhesive 28 or other method in orderto produce a desired effect.

The member 27 may be used to further improve the uniformity of the lightoutput distribution. For example, the member 27 may be a colored film, adiffuser, or a label or display, a portion of which may be a transparentoverlay that may be colored and/or have text or an image thereon.

If adhesive 28 is used to adhere the back reflector 26 and/or film 27 tothe panel, the adhesive is preferably applied only along the side edgesof the panel, and if desired the end edge opposite the light transitionareas 12, but not over the entire surface area or areas of the panelbecause of the difficulty in consistently applying a uniform coating ofadhesive to the panel. Also, the adhesive changes the internal criticalangle of the light in a less controllable manner than the air gaps 30(see FIG. 5) which are formed between the respective panel surfaces andthe back reflector 26 and/or film 27 when only adhered along theperipheral edges. Additionally, longer panel members are achievable whenair gaps 30 are used. If adhesive were to be used over the entiresurface, the pattern of deformities could be adjusted to account for theadditional attenuation in the light caused by the adhesive.

Referring further to FIG. 2, the panel assembly 5 shown therein alsoincludes molded posts 31 at one or more corners of the panel 7 (foursuch posts being shown) which may be used to facilitate mounting of thepanel assembly and providing structural support for other parts orcomponents, for example, a display panel such as a liquid crystaldisplay panel as desired.

FIG. 6 shows another form of light emitting panel assembly 32 inaccordance with this invention including a panel member 33, one or morelight sources 3, and one or more light output areas 34. In addition, thepanel assembly 32 includes a tray 35 having a cavity or recess 36 inwhich the panel assembly 32 is received. The tray 35 may act as a backreflector as well as end edge and/or side edge reflectors for the panel33 and side and/or back reflectors 37 for the light sources 3.Additionally, one or more secondary reflective or refractive surfaces 38may be provided on the panel member 33 and/or tray 35 to reflect aportion of the light around one or more corners or curves in anon-rectangular shaped panel member 33. These secondaryreflective/refractive surfaces 38 may be flat, angled, faceted orcurved, and may be used to extract a portion of the light away from thepanel member in a predetermined pattern. FIG. 6 also shows multiplelight output areas 34 on the panel member that emit light from one ormore light sources 3.

FIG. 7 is a schematic illustration of still another form of lightemitting panel assembly 40 in accordance with this invention including apanel member 41 having one or more light output areas 42 and one or morelight transition areas (mixing areas) 43 containing a plurality of lightsources 3 at one or both ends of the panel. Each transition area mixesthe light from one or more light sources having different colors and/orintensities. In this particular embodiment, each of the light sources 3desirably employs three colored LEDs (red, blue, green) in eachtransition mixing area 43 so that the light from the three LEDs can bemixed to produce a desired light output color that will be emitted fromthe light output area 42. Alternatively, each light source may be asingle LED having multiple colored chips bonded to the lead film. Also,two colored LEDs or a single LED having two colored chips may be usedfor a particular application. By varying the intensities of theindividual respective LEDs, virtually any colored light output or whitelight distribution can be achieved.

FIG. 8 shows yet another form of light emitting panel assembly 45 inaccordance with this invention including a light emitting panel member46 and a light source 3 in a light transition area 48 integral with oneend of the panel member. In this particular embodiment, the panel member46 is three-dimensionally curved, for example, such that light rays maybe emitted in a manner that facilitates aesthetic design of a lighteddisplay.

FIG. 9 schematically shows another form of light emitting panel assembly50 in accordance with this invention, including a panel mender 51 havingmultiple light output areas 52, and mounting posts and/or mounting tabs53. This particular panel assembly 50 may serve as a structural memberto support other parts or components as by providing holes or cavities54, 55 in the panel member 51 which allow for the insertion of modularcomponents or other parts into the panel member. Moreover, a separatecavity or recess 56 may be provided in the panel member 51 for receiptof a correspondingly shaped light transition area 57 having one or morelight sources 3 embedded, bonded, cast, insert molded, epoxied, orotherwise mounted or positioned therein and a curved reflective orrefractive surface 58 on the transition area 57 and/or wall of thecavity or recess 56 to redirect a portion of the light in apredetermined manner. In this way the light transition area 57 and/orpanel member may be in the form of a separate insert which facilitatesthe easy placement of the light source in a modular manner. A reflector58 may be placed on the reflective or refractive surface of the cavityor recess 56 or insert 57. Where the reflector 58 is placed on thereflective or refractive surface of the cavity or recess 56, the cavityor recess may act as a mold permitting transparent material from whichthe transition area 57 is made to be cast around one or more lightsources 3.

FIGS. 10 and 11 schematically show another form of light emitting panelassembly 60 in accordance with this invention including a panel member61 having one or more light output areas 62. In this particularembodiment, an off-axis light transition area 63 is provided that isthicker in cross section than the panel member to permit use of one ormore light sources 3 embedded or otherwise mounted in the lighttransition area that are dimensionally thicker than the panel member.Also, a three-dimensional reflective surface 64 (FIG. 11) may beprovided on the transition area 63. Moreover, a prism 65 (FIG. 11) ortapered, rounded, or otherwise shaped end 66 (FIG. 11a) may be providedat the end of the panel opposite the light sources 3 to perform thefunction of an end reflector. The light sources 3 may be oriented atdifferent angles relative to each other and offset to facilitate bettermixing of the light rays 67 in the transition area 63 as schematicallyshown in FIG. 10 and/or to permit a shorter length transition area 63 tobe used.

FIGS. 12 and 13 schematically show still another form of light emittingpanel assembly 70 in accordance with this invention which includes oneor more light transition areas 71 at one or both ends of the panelmember 72 each containing a single light source 73. The transition areaor areas 71 shown in FIGS. 12 and 13 collect light with multiple orthree-dimensional surfaces and/or collect light in more than one plane.For example each transition area 71 shown in FIGS. 12 and 13 haselliptical and parabolic shape surfaces 74 and 75 in different planesfor directing the light rays 76 into the panel member at a desiredangle.

Providing one or more transition areas at one or both ends of the panelmember of any desired dimension to accommodate one or more lightsources, with reflective and/or refractive surfaces on the transitionareas for redirecting the light rays into the panel member at relativelylow angles allows the light emitting panel member to be made much longerand thinner than would otherwise be possible. For example the panelmembers of the present invention may be made very thin, i.e., 0.125 inchthick or less.

FIG. 14 schematically illustrates still another form of light emittingpanel assembly 80 in accordance with this invention including a lightemitting panel 81 and one or more light sources 3 positioned, embedded,potted, bonded or otherwise mounted in a light transition area 82 thatis at an angle relative to the panel member 81 to permit more efficientuse of space. An angled or curved reflective or refractive surface 83 isprovided at the junction of the panel member 81 with the transition area82 in order to reflect/refract light from the light source 3 into thebody of the panel member 81 for emission of light from one or more lightemitting areas 84 along the length of the panel member.

FIG. 15 schematically illustrates still another form of light emittingpanel assembly 90 in accordance with this invention including a lighttransition area 91 at one or both ends of a light emitting panel member92 containing a slot 93 for sliding receipt of an LED or other suitablelight source 3. Preferably the slot 93 extends into the transition area91 from the back edge 94, whereby the light source 3 may be slid and/orsnapped in place in the slot from the back, thus allowing the transitionarea to be made shorter and/or thinner. The light source 3 may beprovided with wings, tabs or other surfaces 95 for engagement incorrespondingly shaped recesses or grooves 96 or the like in thetransition area 91 for locating and, if desired, securing the lightsource in place. Also, the light source 3 may be embedded, potted,bonded or otherwise secured within the slot 93 in the light transitionarea 91 of the panel member 92. Light from a secondary light source 97may be projected through the panel member 92 for indication or someother effect.

The various light emitting panel assemblies disclosed herein may be usedfor a great many different applications including for example LCD backlighting or lighting in general, decorative and display lighting,automotive lighting, dental lighting, phototherapy or other medicallighting, membrane switch lighting, and sporting goods and apparellighting or the like. Also the panel assemblies may be made such thatthe panel members and deformities are transparent without a backreflector. This allows the panel assemblies to be used for example tofront light an LCD or other display such that the display is viewedthrough the transparent panel members.

Although the invention has been shown and described with respect tocertain preferred embodiments, it is obvious that equivalent alterationsand modifications will occur to others skilled in the art upon thereading and understanding of the specification. The present inventionincludes all such equivalent alterations and modifications, and islimited only by the scope of the claims.

What is claimed is:
 1. A method of planar illumination comprising thesteps of:generating light via a light source; directing generated light,defined by a directional component in each of first and secondrelatively unique axes of a cross-sectional area of an opticalconductor, generally perpendicularly to the cross-sectional area suchthat a component of generated light along the first axis is distributedto a greater extent therealong than a component of generated light alongthe second axis; receiving generated light into a generally planaroptical conductor having at least one pair of generally parallel,opposed walls, the light being received at an angle relative to theopposed walls such that a significant portion thereof is reflectedbetween the opposed walls via internal reflection; and communicatingreceived light through the optical conductor to a preselected pattern ofirregularities associated with the optical conductor to cause light tobe emitted outward therefrom.
 2. The method of claim 1 furthercomprising the step of directing light generated by the light source toa transition area between a first refractive index of an opticallyconductive medium disposed between the light source and the opticalconductor having a second refractive index distinct from the first. 3.The method of claim 2 further comprising the step of concentrating lightof the light source prior to the step of directing light to thetransition area.
 4. The method of claim 3 further comprising the step ofcommunicating light emanating from the irregularities to an associateddisplay secured to the optical conductor so as to illuminate indiciadisposed on the associated display.
 5. The method of claim 4 wherein thestep of communicating received light includes the step of communicatingthe received light through the optical conductor inclusive of a dyedisposed therein.
 6. The method of claim 4 wherein the step ofcommunicating received light includes the step of communicating thereceived light through the optical conductor inclusive of a dispersionmaterial disposed therein.
 7. The method of claim 4 wherein the step ofcommunicating received light includes the step of communicating thereceived light through the optical conductor inclusive of a plurality ofgenerally translucent subareas disposed therein.
 8. A method of planarillumination comprising the steps of:directing light from a light sourceinto an optical conductor at an angle relative to the opposed walls suchthat a significant portion thereof is reflected between the opposedwalls via internal reflection; directing light from the light source,defined by a directional component in each of a first and secondmutually distinct axis of a generally planar cross-section of theoptical conductor, generally perpendicular to light emanating from thelight source; directing a component of light from the light source alongthe second axis to a greater extent than a component of light directedalong the first axis; and a preselected pattern of irregularitiesassociated along the optical conductor to cause light to be emittedoutward therefrom.
 9. A method of planar illumination comprising thesteps of:generating light via a light source; selectively directinggenerated light, defined as having a directional component in each offirst and second axes of a generally planar cross-section of a generallyplanar optical conductor, such that a second component of generatedlight is distributed along the second selected axis generally to agreater extent than a first component distributed along the first axis;receiving generated light that has been selectively generated along theselected axis into a generally planar optical conductor having at leastone pair of generally parallel, opposed walls, the light being receivedat an angle relative to the opposed walls such that a significantportion thereof is reflected between the opposed walls via internalreflection; and communicating received light through the opticalconductor to a preselected pattern of irregularities associatedtherewith.
 10. The method of claim 9 further comprising the step ofdirecting light generated by the light source a transition area betweena first refractive index of an optically conductive medium disposedbetween the light source and the optical conductor having a secondrefractive index distinct from the first so as to accomplish the step ofselectively spreading generated light along a selected axis.
 11. Themethod of claim 10 further comprising the step of communicating lightreflected from the irregularities to an associated display secured tothe optical conductor so as to illuminate indicia disposed on theassociated display.
 12. The method of claim 11 wherein the step ofcommunicating received light includes the step of communicating thereceived light through the optical conductor inclusive of a dye disposedtherein.
 13. A planar illumination system comprising:a generally planaroptical conductor having at least one pair of generally parallel,opposed walls and defining first and second mutually distinct axes of across-sectional area thereof generally perpendicular to a direction oflight propagation; directing means for directing light defined by adirectional component in each of the first and second axes so as to bedistributed over a greater extent along the first axis relative to lightdistribution along the second axis; receiving means for receivingdirected light from the directing means into the optical conductor at anangle relative to the opposed walls such that a significant portionthereof is reflected between the opposed walls via internal reflection;and a preselected pattern of irregularities associated with the opticalconductor to cause light to be emitted outward therefrom.
 14. The planarillumination system of claim 13 wherein the preselected pattern of lightscattering irregularities includes a dye interspersed within the opticalconductor.
 15. The planar illumination system of claim 13 wherein thepreselected pattern of light scattering irregularities includes adispersion material disposed within the optical conductor.
 16. Theplanar illumination system of claim 13 wherein the preselected patternof light scattering irregularities includes a plurality of generallyopaque subareas.
 17. The planar illumination system of claim 13 whereinthe preselected pattern of light scattering irregularities includes aplurality of generally translucent subareas.
 18. The planar illuminationsystem of claim 13 further comprising:a light source adapted to generatelight to the directing means; and wherein at least one of the directingmeans and the receiving means is comprised of a light reflector.
 19. Theplanar illumination system of claim 13 wherein the at least one pair ofgenerally parallel, opposed walls are curved.
 20. The planarillumination system of claim 13 further comprising:a light sourceadapted to generate light to the directing means; and wherein at leastone of the directing means and the receiving means includes a transitionarea between a first refractive index of an optically conductive mediumdisposed between the light source and the optical conductor having asecond refractive index distinct from the first.
 21. The planarillumination system of claim 20 further comprising means adapted forsecuring an associated display to the optical conductor so as toilluminate indicia disposed on the associated display via lightemanating from the preselected pattern.
 22. A planar illumination systemcomprising:a generally planar optical conductor having at least one pairof generally parallel, opposed walls; a light source; directing meansfor directing light from the light source into the optical conductor atan angle relative to the opposed walls such that a significant portionthereof is reflected between the opposed walls via internal reflection,the directing means including,means for directing light, defined by adirectional component in each of first and second mutually distinct axesof a generally planar cross-section of the optical conductor, from thelight source to the generally planar cross-sectional area generallyperpendicular to a direction of propagation of light from the lightsource, and means for directing light from the light source such thatlight thereof is distributed along the second axis to a greater extentthan a distribution of light along the first axis; and a preselectedpattern of irregularities associated along the optical conductor tocause light to be emitted therefrom.
 23. The planar illumination systemof claim 22 whereinthe direction means is formed by a transition areabetween a first refractive index of an optically conductive mediumdisposed between the light source and the optical conductor having asecond refractive index distinct from the first.
 24. An illuminationsystem comprising:a light source; a semi-transparent visual displayhaving an indicia set of at least one of text or character indicadisposed thereon; a generally planar optical conductor having at leastone pair of generally parallel, opposed walls; directing means fordirecting light, defined by a directional component in each of first andsecond mutually distinct axes of a generally planar cross-section of theoptical conductor, such that a light component is distributed along thesecond axis to a greater extent than a light component distributed alongthe first axis; receiving means for receiving directed light from thedirecting means into the optical conductor at an angle relative to theopposed walls such that a significant portion thereof is reflectedbetween the opposed walls via internal reflection; and a preselectedpattern of irregularities associated the optical conductor and orderedto correspond with the indica set such that the indicia is illuminatedfrom light emitted from the irregularities.
 25. The illumination systemof claim 24 wherein the indicia set is comprised of a flat-panel videodisplay terminal.
 26. The illumination system of claim 25 wherein theindicia set is comprised of an instrument panel display.